Chapter 16: Excretory Products and their Elimination Assertion-Reason Questions | biology Class 11 CBSE

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 1

Logic Check

Assertion (A): Ammonia is excreted by diffusion across body surfaces in ammonotelic animals and kidneys play no significant role. Reason (R): Ammonia is readily soluble in water and is generally excreted as ammonium ions through gill or body surfaces.

Reasoning Options

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Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 2

Logic Check

Assertion (A): Uricotelic animals include reptiles, birds, land snails, and insects. Reason (R): Uric acid is the most toxic nitrogenous waste and requires the maximum amount of water for its elimination.

Reasoning Options

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Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 3

Logic Check

Assertion (A): Each human kidney contains nearly one million nephrons. Reason (R): The nephron is the functional unit of the kidney responsible for urine formation.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 4

Logic Check

Assertion (A): Glomerular filtration is considered a process of ultrafiltration. Reason (R): All constituents of blood including plasma proteins are filtered into the Bowman's capsule by the glomerulus.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 5

Logic Check

Assertion (A): GFR in a healthy human is approximately 125 mL/minute. Reason (R): The JGA releases renin to increase GFR when it falls below normal levels.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 6

Logic Check

Assertion (A): The descending limb of Henle's loop concentrates the filtrate as it moves downward. Reason (R): The descending limb is permeable to water but almost impermeable to electrolytes.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 7

Logic Check

Assertion (A): The ascending limb of Henle's loop is impermeable to water. Reason (R): This impermeability allows the ascending limb to dilute the filtrate while simultaneously enriching the medullary interstitium with electrolytes.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 8

Logic Check

Assertion (A): PCT reabsorbs 70-80% of electrolytes and water from the filtrate. Reason (R): PCT is lined by simple squamous epithelium that reduces the surface area for reabsorption.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 9

Logic Check

Assertion (A): Vasa recta is absent or highly reduced in cortical nephrons. Reason (R): Cortical nephrons have a short Henle's loop that does not extend deep into the medulla, reducing the need for counter current exchange.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 10

Logic Check

Assertion (A): ADH facilitates water reabsorption from the latter parts of the tubule, thereby preventing diuresis. Reason (R): ADH is released from the anterior pituitary in response to increased blood osmolarity.

Reasoning Options

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Assertion-Reason

Hard difficulty • Check the statement and reason

Hard

Question 11

Logic Check

Assertion (A): Angiotensin II is a powerful vasoconstrictor that increases glomerular blood pressure and GFR. Reason (R): Angiotensin II is formed from angiotensinogen directly by the action of aldosterone.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 12

Logic Check

Assertion (A): ANF mechanism acts as a check on the renin-angiotensin mechanism. Reason (R): ANF causes vasodilation and thereby decreases blood pressure, opposing the vasoconstrictive action of angiotensin II.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 13

Logic Check

Assertion (A): Micturition is a completely involuntary process that cannot be controlled voluntarily. Reason (R): The stretch receptors in the urinary bladder send signals to the CNS, which coordinates the micturition reflex.

Reasoning Options

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Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 14

Logic Check

Assertion (A): Presence of ketone bodies in urine (ketonuria) indicates diabetes mellitus. Reason (R): In diabetes mellitus, excessive fat catabolism produces ketone bodies that accumulate and are excreted in urine.

Reasoning Options

ByteNotes

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 15

Logic Check

Assertion (A): The liver performs an excretory function in the human body. Reason (R): The liver secretes bile containing bilirubin, biliverdin, cholesterol, and degraded steroid hormones which are eliminated with digestive wastes.

Reasoning Options

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Assertion-Reason

Hard difficulty • Check the statement and reason

Hard

Question 16

Logic Check

Assertion (A): Hemodialysis completely replaces the function of a healthy kidney in patients with renal failure. Reason (R): The dialysing fluid in hemodialysis has the same composition as plasma except that it lacks nitrogenous wastes.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 17

Logic Check

Assertion (A): The collecting duct allows passage of small amounts of urea into the medullary interstitium. Reason (R): Urea contributes to the maintenance of the osmolarity of the medullary interstitium necessary for water reabsorption.

Reasoning Options

ByteNotes

Assertion-Reason

Easy difficulty • Check the statement and reason

Easy

Question 18

Logic Check

Assertion (A): Renal calculi are formed by the crystallization of insoluble salts within the kidney. Reason (R): Renal calculi are composed of crystallized salts such as oxalates.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 19

Logic Check

Assertion (A): Terrestrial animals generally excrete urea or uric acid rather than ammonia. Reason (R): Ammonia is the least toxic nitrogenous waste and requires the least water for elimination, making it unsuitable for land-dwelling animals.

Reasoning Options

ByteNotes

Assertion-Reason

Medium difficulty • Check the statement and reason

Medium

Question 20

Logic Check

Assertion (A): Juxtamedullary nephrons play a more important role in urine concentration than cortical nephrons. Reason (R): Juxtamedullary nephrons have a very long loop of Henle that runs deep into the medulla, contributing to the medullary osmotic gradient.

Reasoning Options

ByteNotes

Chapter sections

Chapter 16: Excretory Products and their Elimination | Assertion-Reason

Assertion (A): Ammonia is excreted by diffusion across body surfaces in ammonotelic animals and kidneys play no significant role. Reason (R): Ammonia is readily soluble in water and is generally excreted as ammonium ions through gill or body surfaces.

Assertion (A): Uricotelic animals include reptiles, birds, land snails, and insects. Reason (R): Uric acid is the most toxic nitrogenous waste and requires the maximum amount of water for its elimination.

Assertion (A): Each human kidney contains nearly one million nephrons. Reason (R): The nephron is the functional unit of the kidney responsible for urine formation.

Assertion (A): Glomerular filtration is considered a process of ultrafiltration. Reason (R): All constituents of blood including plasma proteins are filtered into the Bowman's capsule by the glomerulus.

Assertion (A): GFR in a healthy human is approximately 125 mL/minute. Reason (R): The JGA releases renin to increase GFR when it falls below normal levels.

Assertion (A): The descending limb of Henle's loop concentrates the filtrate as it moves downward. Reason (R): The descending limb is permeable to water but almost impermeable to electrolytes.

Assertion (A): The ascending limb of Henle's loop is impermeable to water. Reason (R): This impermeability allows the ascending limb to dilute the filtrate while simultaneously enriching the medullary interstitium with electrolytes.

Assertion (A): PCT reabsorbs 70-80% of electrolytes and water from the filtrate. Reason (R): PCT is lined by simple squamous epithelium that reduces the surface area for reabsorption.

Assertion (A): Vasa recta is absent or highly reduced in cortical nephrons. Reason (R): Cortical nephrons have a short Henle's loop that does not extend deep into the medulla, reducing the need for counter current exchange.

Assertion (A): ADH facilitates water reabsorption from the latter parts of the tubule, thereby preventing diuresis. Reason (R): ADH is released from the anterior pituitary in response to increased blood osmolarity.

Assertion (A): Angiotensin II is a powerful vasoconstrictor that increases glomerular blood pressure and GFR. Reason (R): Angiotensin II is formed from angiotensinogen directly by the action of aldosterone.

Assertion (A): ANF mechanism acts as a check on the renin-angiotensin mechanism. Reason (R): ANF causes vasodilation and thereby decreases blood pressure, opposing the vasoconstrictive action of angiotensin II.

Assertion (A): Micturition is a completely involuntary process that cannot be controlled voluntarily. Reason (R): The stretch receptors in the urinary bladder send signals to the CNS, which coordinates the micturition reflex.

Assertion (A): Presence of ketone bodies in urine (ketonuria) indicates diabetes mellitus. Reason (R): In diabetes mellitus, excessive fat catabolism produces ketone bodies that accumulate and are excreted in urine.

Assertion (A): The liver performs an excretory function in the human body. Reason (R): The liver secretes bile containing bilirubin, biliverdin, cholesterol, and degraded steroid hormones which are eliminated with digestive wastes.

Assertion (A): Hemodialysis completely replaces the function of a healthy kidney in patients with renal failure. Reason (R): The dialysing fluid in hemodialysis has the same composition as plasma except that it lacks nitrogenous wastes.

Assertion (A): The collecting duct allows passage of small amounts of urea into the medullary interstitium. Reason (R): Urea contributes to the maintenance of the osmolarity of the medullary interstitium necessary for water reabsorption.

Assertion (A): Renal calculi are formed by the crystallization of insoluble salts within the kidney. Reason (R): Renal calculi are composed of crystallized salts such as oxalates.

Assertion (A): Terrestrial animals generally excrete urea or uric acid rather than ammonia. Reason (R): Ammonia is the least toxic nitrogenous waste and requires the least water for elimination, making it unsuitable for land-dwelling animals.

Assertion (A): Juxtamedullary nephrons play a more important role in urine concentration than cortical nephrons. Reason (R): Juxtamedullary nephrons have a very long loop of Henle that runs deep into the medulla, contributing to the medullary osmotic gradient.

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